Photos of Surviving N.28's

History

By mid 1917, the series of sesquiplane fighters created by Gustave Delage had reached it's end with the Nieuport 27. In 1915 and 1916 the Nieuport 11 and it's successor the Nieuport 17 were renowned for their manoeverability. However, by the time the Nieuport 27 reached allied squadrons the Spad 7 had surpassed it in overall performance and ruggedness. A fundamental change was required if the fighters produced by the Societe Anonyme des Establissements Nieuport were to remain competitive. To this end a new model was created.

The Gnome Type 9N Monosoupaupe was selected to power the new model and the wing area was increased to 16 square meters. The distinctive V-struts associated with Nieuports earlier models were replaced with parallel struts and the wing tips were elliptical in contrast to the angular wing tips of it's predecessors. The ailerons were moved from the upper wing to the lower wing where they were activated by torque tubes which like the rest of the Nieuports controls were routed internally and contributed to it's clean lines. Due to the aircraft's small size two machine guns and the associated ammunition bins and feed trades could not be fit in the traditional location. As a result one machine gun was fit on the upper forward fuselage and a second machine gun was added and placed distinctively on the lower left fuselage side. The fuel was contained in two tanks; a primary tank of 85 liters and an auxiliary tank of 45 liters.(31) Fuel was pulled from the lower (auxiliary) tank by a Weyman exhauster, which in turn made use of the low pressure created in the throat of a venturi. This was certainly one of the earliest aircraft uses for a venturi.

After several revisions, the new fighter was accepted by the Aviation Militaire Francaise which gave it the numerical designation of Nieuport 28C.1 and ordered it into production. The order was canceled shortly afterward. Althought the Nieuport 28's performance was an improvement over that of it's predecssors, it was regarded as inferior to the Spad XIII with which the French Air Service was largely equiped. Rejected by the French Air Service, the N.28 became the first operation fighter with the American Expeditionary Force simply because they were available. The USAS purchased 287 Nieuport 28's for $18500 each (1).

The first squadron to receive the fighter was the 95th Aero in late February 1918. By mid march a second squadron, the 94th Aero received it's first compliment of Nieuports. Neither unit received any machineguns until late March. The lack of weapons did not prevent the American squadrons from flying, in fact each squadron conducted unarmed patrols over the lines, which were flown 'in the interest of morale.' Eventually machine guns arrived, although at first their were only enough to outfit each plane with but one gun. The 94th flew it's first armed patrol on March 28. On April 14, Lt Campbell scored the first kill for an American unit when he downed a Pfalz D.IIIa in the vicinity of his aerodrome.

Service Issues

The N.28 had several service problems. Most remembered among them was the failure of the upper wing in a dive, the leading edge seperated from the aircraft pulling the fabric off the wing. This failure occurred at least six times (Meissner twice, and once each to Hall, Rickenbacker, Heinrichs and Casgrain.) In each case the failure occurred during a pull up from a power on dive. It was not the dive, but the pull out that wrecked the wing. There are several accounts of vertical dives, for instance Hartney states 'I was soon showing the squadron how this ship could dive vertically at the ground' (2); from this it can be infered that it was possible to safely dive this airplane as long as care was taken with the pull out.

Despite the grotesque appearance of the failed upper wings in most cases control of the aircraft was maintained and the machines were safely landed. Had the ailerons been on the top wing like in pervious models this failure would have been much worse. The failure seems to have been limited to the ships of the 94th and 95th. It is quite possible that either the design had been improved by the time aircraft were delivered to the 27th/147th or as Hartney suggests these squadrons pilots were better prepared to cope with their machine's flaw. Hartney proudly noted 'no Nieuport of ours ever stripped it's wings'(3).

Other service failures include a blown engine cylinder (Lufbery), broken valves (Heinrichs) and many recorded occurances of magneto failure. There were also a number of landing accidents and at least one notable in flight fire (Lufbery) which was commonly attributed to a bullet passing through the fuel tank.

The Gnome Monosoupape was a reliable engine for it's day, however it had it's quirks. The Monosoupape like other rotaries of it's day did not have a throttle in the traditional sense. In it's place it had the ability to control ignition. This was accomplished through a blip switch; pressing the blip switch grounded the magneto and prevented ignition. However this did not stop the flow of fuel, as a result the unburnt fuel flowed out through the exhaust port. If the pilot was aggressive in his use of the blip switch and neglected to shut off the flow of fuel a combustible mixture accumulated within the cowling and inevitably a fire resulted. Another known problem with the wartime production Gnome Monosoupaupe was that its copper fuel lines were often improperly annealed. These fuel lines then cracked and often led to a fire as fuel poured onto the hot motor. It was also noted that the engine had a tendancy to catch fire upon starting.(4) The gnome was virtually free from carburator ice due to the fact that the air entered in the center, and passed into the warm crank case before mixing with fuel. (22)

The time between overhaul varied between twelve hours for the factory mechanics and thirty hours for the mechanics of the 27th Aero (5). The overhaul required 4 hours which was substantially less than the four days required to overhaul the Hispano-Suiza used in the Spad (6). When the 27th transitioned from the Nieuport to the Spad the number of machines available for patrol dropped from 90% to 50%.(6)

Performance

Combat experience showed the N.28 to have outstanding manoeverability, an excellent rate of climb and a respectable top speed. Major Hartney, the comander of the 27th Aero (and later the 1st Pursuit Group) summed up the aircraft when he described the Nieuport 28 as "a fast moving, fast acting gem" (7). What this means in absolute terms and how this and other early airplanes actually performed is a matter for debate. However, there are clues available in the writings of the day. Included below is a summary of comparisions distilled from books that were written during or shortly after the war. At the very least the table below indicates how pilot's in that day and age viewed the airplane they flew as it compared with other aircraft.

The N.28 clearly benefited from good manueverability and an impressive rate of climb, however it was not considered as rugged as the Spads which replaced it. A flight test (19) of a prototype which weighed about 48 lb less (20) than the version the USAS adopted yielded the following results:

The maximum altitude listed in the report was 22,310 ft (6800m). Surviving reports from the pilots indicates that the maximum altitude may have been slightly lower. For instance Rickenbacker lamented the fact that a particular Rumpler observation plane in which he had taken an interest flew at 20000 ft and could still climb while his Nieuport could reach only 18000 ft. According to him: 'Some Nieuports have a higher ceiling than others. It depends upon the quality and natural fitness of the motor. My bus reached 18,000 feet that mourning. It had just been fitted with two Vickers...' (21). Rickenbacker experimented with other N.28's assigned to his squadron and found that one machine (Lt Smyth's) could reach 20,000 ft with combat load (including 2 machien guns) while another airplane (Capt Marr's) could only make it to 19,000 ft with combat load. Differences in rigging, engine adjustment, instrument calibration, and pilot technique may be to blame for the differences that Rickenbacker noted.

According to Rickenbaker the N.28 carried oil for 2 hours 15 min of flight (23). At one point he flew the machine until the engine seized which resulted in a 2 hour 35 minute flight. Hartney's book mentions a mission of 2 hours 14 minutes (24) as well as at least one mission of 2 hours.

Retirement and Post War History

In mid July 1918, the 94th and 95th retired their Nieuports in favor of Spad XIII's. Rickenbacker, then commander of the 94th was elated to transition into a Spad XIII which he observed could outdive the Nieuport. He felt that the Spad was a more rugged airframe.(25) In early August, the 27th and 147th also retired their Nieuports in favor of the Spad XIII. While the 94th and 95th welcomed the Spads the men of the 27th and 147th were 'heartbroken' over what Hartney described as a 'catastrophe.'(26) In fact Maj Bonnel of the 147th complained bitterly enough about the change that he was relieved of command and transferred to the unnery school at St Jean det Mont on July 22 (27). His replacement 1LT Meissner who had twice survived the loss of his top wing fabric had no complaints about transitioning the 147th into Spads.

At the time of the Armistace, the US Army placed an order for an additional 600 Nieuports (N.28A.1) which had several minor improvements. Including an improved upper wing leading edge structure and a redesign of the fuel system to incorporate an under seat tank in favor of the side mounted auxiliary tank. In addition Marlin machine guns were installed in place of the Vickers. After the war a number of these Nieuports were brought to America were the army operated them as trainers for a short time. The post-war shipment of Nieuports to the states is significant because at that time there was an excess of fighter aircraft in France; the fact that the USAS selected some of it's Nieuports for shipment to America indicates that they were selecting them in preference to other designs that had been in use with the Air Service.

Twelve of the Army Nieuports were transfered to the US Navy which equipped them with hydro vanes to prevent a nose over in the event of a water landing and wing floatation gear. The Navy then flew them from specially built platforms that were mounted above the forward turrets of 8 battleships, including the Oklahoma, Arizona and Pennsylvania. These aircraft once launched from one of these platforms were considered expendible. They had no provision for landing on the ships. When a land base was not within range the pilots were expected to ditch and await rescue.

The N.28 also served with both the Royal Hellenic Air Force and the Swiss airforces in the 1920's. Switzerland retired it's last N.28 from active service in 1930. Meanwhile in America, a number of N.28's made their way to Hollywood where they appeared in the movie 'The Dawn Patrol' as well as in several other pictures.

Notes

(1) "Up and at Em" by Harold Hartney, 1940
(2) "Up and at Em" p.146
(3) "Up and at Em" p.195
(4) "First to the Front" by Charles Woolley, 1999. See Lt Buckley's letter on p.113
(5) "Up and at Em" p.167
(6) "Up and at Em" p.196
(7) "Up and at Em" p.143
(8) "First to the Front" p.72
(9) "Fighting the Flying Circus" vy Edward V Rickenbacker, 1919. See Chap 3: 'the Nieuport can outmaneuver a Spad and has a little faster climb.'
(10) "First to the Front" p.122
(11) "Fighting the Flying Circus", Chap 3; 'Nieuport can out-climb an Albatros (D series) and out maneuver him while doing so'
(12) "Up and at em" p.162
(13) "Up and at Em" Hartney observed that combat loaded nieuport's were faster than an unarmed camel (p.181)
(14) "Up and at Em" p.145 ...his two-gun ship 'climbed even better than the Camel's at Gosport'
(15) "Up and at Em" Hartney stated "To offset this we had the superior maneuverability of our faster and better climbing little Niuports against the sluggishness of the Boche Fokker D.VII's", p.171
(16) "Fighting the Flying Circus" Rickenbacker observed that the Nieuport can turn/twist with more agility than the Rumpler observation machine compared to which it was also observed that the Nieuport was both faster and faster in a dive (chap 13).
(17) "Fighting the Flying Circus" Rickenbacker observed (chap 10) that his Nieuport had far greater speed than the observation albatros.
(18) "Fighting the Flying Circus" Rickenbacker noted that the Pfaltz (D.III) could outdive the Nieuport (chap 4).
(19) See test report dated oct/nov 1917 on this website. Units were changed to ft, fpm and mph. Climb rate was calculated for each increment by dividing the distance to be traveled (1000m) by the time required for that altitude band.
(20) The prototype had only one Vickers which with it's associated ammo weighed approx 88 lb. However it also had an additional fuel tank containing 25L of fuel. 25L is about 6.6 US gal which weighs approximatly 40 lb. 88-40=48 lb. the 228 Kg load listed in the report matches well with the expected full fuel/combat load/pilot weight.
(21) "Fighting the Flying Circus" chap 15.
(22) "Contact" by Villard, 1968.
(23) "Fighting the Flying Circus" chap 14
(24) "Up and at Em" p.154
(25) "Fighting the Flying Circus"
(26) "Up and at Em" p.195 "an now another catastrophe befell the squadron - they took away our beloved Niuports and gave us 220 hp gear driven spads."
(27) "Up and at Em"
(28) Areas based on Bergen Hardesty prints in the Collection of the Air and Space Museum.
(29) Including both wings, both ailerons and lower wing area blanketed by fuselage.
(30) Including ailerons and lower wing area blanketed by fuselage.
(31) The Windsock N.28 Datafile indicates the auxiliary tank was 45L.